This invention relates to a label holder for mounting on channels of shelves for shelf units and the like. Typical shelf units are Lozier or Madix brand shelving units that provide arcuate shelf channels (a.k.a. “C-channels”) for holding product information labels or for holding label holders for replaceable labels that are insertable into a clear sleeve. Label holders are typically extruded from a resilient plastic and include at least a clear front panel behind which a product information label can be inserted. Known label holders can be difficult to install and if they are easy to install, they may be unstable or subject to dislodging. What is needed is an improved label holder design with ease of installation and robust stability.